Steroid aldehydes and process



Patented Apr. 13, 1 954 UNITEDQSTATES PATENT OFFICE.

STEB OID ALDEHYDES AND PROCESS Robert B. Woodward, Belmont, Mass., assignor to Research corporation, New York, N. 'Y., a corporation of New York No Drawing. Application May 19, 1953,

a Serial No. 356,086

Claims. (01. mam-397.45) 2 k This application relates to methods and comto the dialdehyde (IV) by oxidation with pe pounds useful in theproduction of steroids. riodic acid in an aqueous organic solvent.

In application Serial No. 220,977 filed April 13, 1951, is disclosed methods and compounds whereby the cis-adduct of lB-butadiene and Z-methyl- 5 5-methoxybenzoquinone may be converted into lACHPOH/O a D-homosteroid of the formula l The dialdehyde (IV) is cyclized by heating in an organic solvent, preferably inthe presence of a carboxylic acid salt of an organic nitrogen base,

to the 17-a1dehyde steroid (V) (3 keto 16,17 dihydroxy A -D homo- 0H0 androstadiene acetonide) capable of further con- 1 version into steroid hormones. This application relates to methods whereby I v the D-homosteroid (I) may be converted to;

progesterone and related steroids and to the use-, ful intermediate products thereby produced.

The D-homosteroid (I) is hydrogenated in the HO-V presence of palladium black and an alkalito the A/B-cis dihydro derivative (II) I V l I O The aldehyde steroid (V) lslhydrogenated to i \CH 39 the 16,17-dihydro derivative (VI) 3 1110 'II The dihydro derivative (11) "is reduced by I lithium aluminum hydride to the 3a-hydroxy derivative (III) I o )om v I O/C\CH3 and the 16,17-dihydro compound (VI) isreacted (\l Withmethyl magnesium iodide to give'a mixture of 0-20 epimeric A -pregnene-3u,20dio1s,

which are hydrogenated to the pregnane-3a-2G- \/l diois and the latter oxidized with chromic acid to H am pregnane-3,20-dione. The latter may be converted by well .knownmethods of bromination The 3a-hydroxy derivative (III) is converted and debrominationto progesterone.

The following specific examples are illustrative of the methods and compounds of the invention:

3 -Iceto-16,1 7-dihydroxy-A -hmoandrostene acetom'de (II) A suspension of 23 mg. of palladium black in 20 ml. of absolute methanol is made basic by the addition of two drops of a aqueous solution of sodium hydroxide, 133.4 mg. of the diene (I) is added, and the mixture shaken in an atmosphere of hydrogen until the. absorption of hydrogen ceases. Celite is added, the solution is filtered and the filtrate is evaporated to dryness. The product is chromatographed on five grams of neutral alumina and the benzene eluate frac tionally recrystallizes from isopropyl ether yielding 118 mg. of II; M. P. 152-153 C. A catalyst of 2% palladium on strontium carbonate maybe substituted for the palladium black.

3a,16,17 trz'hydroxy A homoandrostene acetom'de (III) A solution of 143.2 mg. of II in 10 cc. of anhydrous ether is added during five minutes to a stirred solution of lithium aluminum hydride in cc. of ether and the mixture stirred for 45 minutes at 30 C. Ethyl acetate is added until the vigorous reaction ceases; then a saturated solution of sodium, sulfate is added until the fiocculent material settles/forming a viscous tar. The ether layer is decanted and the residual tar is washed several times with ether. The ether phase is washed with water until the wash water is neutral, each aqueous phase being in turn washed with ether, and the ether extracts combined and dried with anhydrous sodium sulfate. Evaporation of the ether gives 150 mg. of a crystalline product whichon recrystallization .from isopropyl ether melts at l72-174 C.

30:. hydrozry 17 jormyl A a androsta- -'dz'cne (V) A solution of 325.5 mg. of 111 in 20 cc. of dioxane is cooled to 0 C., a solution of 450 mg. of periodic acid dihydrate in 5 cc. of water is added and the solution is held at 5 C. in atmosphere of nitrogen for twenty hours. The solution is extracted with ether and the etherphase washed with 10% aqueous bicarbonate solution and then with water. The aqueous solutions are extracted with ether and the extracts combined with the main ether extract. The ether is evaporated and the resulting tarry material containing the dialdehyde (IV) is dried in a vacuum desiccator. The dialdehyde has not been obtained in crystalline form.

The dialdehyde (IV) is dissolved in cc. of anhydrous benzene, a mixture of glacial acetic acid (4 drops), piperidine (3 drops) and anhydrous sodium sulfate (2 g.) is added and the mixture held at 50 C. for three hours in a nitrogen atmosphere. The cyclization takes place similarly at lower temperatures but at a slower rate. Ether is added and the resulting solution is washed successively with aqueous hydrochloric acid (0.1 N), aqueous sodium carbonate (10%) and water. The ether solution is dried and the ether evaporated giving a crystalline product which on recrystallization from ether-petroleum ether gives 202 mg. of the aldehyde (V); melt ing point 182-184 C.

hyde (V) in. 25 cc. of benzene is shaken with 722 mg. of palladium-strontium carbonate catalyst in hydrogen at 27 C. After ten minutes the brown catalyst turns black and hydrogen absorption starts, continuing until one mole of hydrogen has been absorbed. The catalyst and solvent are removed leaving a tarry residue containing the A -androstene derivative (VI).

sru) p egnene-3 u,20-di0l A solution of 451 mg. of the androstene (VI) m 15 cc. of anhydrous'ben'zeneis added to a solution'of methyl magnesium bromide in 30 cc. of anhydrous ether and the resulting suspension is'refiuxed for ninety minutes. Additional ether isadded and the mixture is washed with aqueous hydrochloric acid (0.5 N), aqueos sodium carbonate (10%) and water. The ether solution is dried and the solvent evaporated leaving a glass containing the (3-20 epiisomers of A -pregnene- 30;,20-di0l. l g

- A -Pregnene-3,20-dione A solution of 217 mg. of the mixed isomers o1 A -pregnene3,20-diolin 15 cc. of acetonitrile is cooled to 10 C. and a 1.5 N solution of chromic acid in 12 N sulfuric acid is added 'dropwise until a permanent yellow color appears in the organic phase, requiring about four equivalents of chromic acid. The color is discharged with isopropanol, the phases separated and the organic layer Washed with sodium carbonate solution (10%) and water, and then dried over anhydrous sodium sulfate. The solventismemoved yielding 20 mg. of crude pregnene dione, which when chromatographed on 6 g. of neutral alumina, eluted with 50% benzene-50% petroleum ether, and crystallization from ether melted at 125-127 C.

3u,20-pregnahediol To a solution of the mixed isomers of A pregnene-3c,20-diol in 20.00. of glacial acetic acid is added 300 mg. of platinum oxide and the mixture is shaken in hydrogen at C. and 50 p. s. i. for ninety minutes. One gram of Celite is added, the solid filtered off and the solution evaporated under vacuum to a glassy residue. This is dissolved in ethanol (10 00.); water is added 10 cc.), then sodium hydroxide (1 g.) and the mixture refluxed under nitrogen for one hour.

The aqueous phase is separated and extracted with chloroform and ethyl acetate. The combined extracts are washed with dilute hydrochloric acid (1.0 N) and then with a saturated solution of sodium sulfate. After drying over anhydrous sodium sulfate the solvent is removed leaving a tar containing the isomeric 3u,20-pregnanediols.

3,20-pregnanedione I 5 6 I claim: boxylic acid salt of an organic nitrogen base and 1. Compounds of the group consisting of the recovering the 17-aldehyde steroid thereby pro- 17-aldehyde steroids of the formula duced.

CH 4. The method which comprises heating a solution of a compound of the formula -OHrCHO and H0- in an aromatic hydrocarbon solvent in the presence of a carboxylic acid salt of an organic nitrogen base and recovering the 17-aldehyde steroid A I thereby produced. 6,) 20 5. The method which comprises heating a solution of a compound of the formula 2. The 17-aldehyde steroid of the formula CHO l GH:OHO I l I Hoin an aromatic hydrocarbon solvent in the presence of piperidine acetate nitrogen base and re- 3. The method which comprises heating a solucovering the 'aldehyde Steroid thereby ticn of a compound of the formula duced' References Cited in the file of this patent "CHFCHO UNITED STATES PATENTS 40 'Number Name Date 2,337,271 Reichstein Dec. 21, 1943 11 2,344,992 Logemann Mar. 28, 1944 H 2,533,124 Levin Dec. 5, 1950 2,623,054 Levin Dec. 23, 1952 in an organic solvent in the presence or a car- 

1. COMPOUNDS OF THE GROUP CONSISTING OF THE 17-ALDEHYDE STEROIDS OF THE FORMULA 